Palaeoenvironmental and palaeohydrological variability of mountain areas in the central Mediterranean region: A 190 ka-long chronicle from the independently dated Fucino palaeolake record (central Italy)

Abstract

Proxy records of past climate change spanning beyond the radiocarbon range commonly derive their chronologies from orbital tuning strategies, thus bounding our spatio-temporal reconstructions to a priori assumptions that can not be directly tested. Here we present a tephrochronologically constrained framework of past environmental and climatic changes in the central Mediterranean region during the last ca. 190 ka. Our research is based on a high-resolution, multi-proxy study of a sedimentary record (cores F1-F3) retrieved from the Fucino Basin lacustrine succession, central Italy, in 2015. We update the existing tephrostratigraphic framework of the F1-F3 record with the finding of the widespread Campanian Ignimbrite tephra marker layer and produce a robust and independent chronology based on new and published 40Ar/39Ar and 14C dating of 17 tephra layers. Observed palaeoenvironmental changes are tracked in other lacustrine, marine and speleothem records across the Mediterranean and North Atlantic regions via tephrostratigraphic correlations and chronological matching providing a robust assessment of age uncertainties. Results show a complex interplay between local environmental changes and broad-scale climatic processes highlighting a strong orbital forcing on glacial-interglacial changes. Along with these major changes we detect prominent millennial-scale variability. During times of intermediate global ice volumes, Mediterranean mountain ecosystems oscillated around an “interglacial” state suggesting that climatic shifts, although large, did not exceed the local environmental tolerance-resilience threshold. Conversely, during periods of large global ice volume, we observe subdued millennial-scale variability with ecosystems operating in a strictly ruled glacial environment.